1. Field of the Invention
The present invention relates to a permanent-magnet type brushless motor in which a multi-pole anisotropic magnet is used for a rotor and a stator core is covered by an insulator, and to an air conditioner using the motor.
2. Description of the Prior Art
A conventional permanent-magnet type brushless motor disclosed in Japanese Patent Application Laid-Open No. 5-344702 in which a stator core is molded by using a resin and the motor disclosed in Japanese Unexamined Utility Model Publication No. 2-88437 in which a rotor is formed by integrally molding a cylindrical magnet and a shaft by inserting a resin are known.
The former known technique is effective with respect to points that the influence by noises generated from the motor is reduced and noises entering from the outside into the motor are checked, however, since the core is molded, the weight is relatively heavy. The motor is difficult to be disassembled and recyclability is not sufficiently considered.
The point of the latter known technique is to open a drill hole in the shaft in order to enhance the connecting force with the shaft when the cylindrical magnet and the shaft are molded by inserting a resin. However, suppression of the rotor vibration is not considered.
It is an object of the invention to provide an efficient permanent-magnet type brushless motor having lighter weight and higher recyclability in which lightness, improvement in assembling performance, low vibration, and the like are generally reexamined.
The one object of this invention is to supply an air conditioner with higher safety.
According to an aspect of the present invention, the object of the invention is achieved by a permanent-magnet type brushless motor having a rotor obtained by integrally forming a rotating magnetic pole constructed by a cylindrical multi-pole anisotropic magnet and a shaft by a cylindrical casing holding therein a stator core and an elastic insulating supporting member having rigidity lower than at least that of the shaft.
Preferably, the cylindrical casing is constructed by two divided cup-shaped synthetic resin members which are fixed so as to face each other while sandwiching the stator core.
Preferably, the cylindrical casing member is made of a non-magnetic material having the specific gravity at least ranging from 0.8 to 3.
Preferably, the cylindrical casing includes a material which suppresses electromagnetically radiated noises generated during operation on the basis of a rotational control frequency.
Preferably, the cylindrical casing is divided into two by an almost vertical line in the axial dimension of the rotor, a mounting flange for a rotor and a boss to be attached to the divided-half of the casing are integrally formed in the other divided-half of the casing, a loop slot is formed on one of the division faces, a projection is formed on the opposite face, and the loop slot and the projection are fit with each other and connected.
Preferably, the rotor mounting flange has a vibration damping member, and the vibration damping member comprises a thin-walled circular tube arranged in the center part and a vibration absorbing member which is closely attached to the thin-walled circular tube and has a plurality of through holes extending in the axial direction on the outer periphery.
According to another aspect of the present invention, there is provided a permanent-magnet type brushless motor having a rotor by integrally forming a rotating magnetic pole constructed by a cylindrical multi-pole anisotropic magnet and a shaft by a cylindrical casing made of a resin which holds a stator core and an elastic insulating member having rigidity lower than at least that of the shaft, wherein a stator coil wound around the stator core is of a coil insulating kind having a flash point temperature lower than that of an insulating resin member provided between the lowest layer of the coil and the stator core and that of the cylindrical resin casing.
Preferably, a lead wire of the stator coil is collected at a wiring terminal fixed to the end face of the stator coil and is led to the outside.
According to another aspect of the present invention, the invention is realized by a permanent-magnet type brushless motor comprising: a wiring terminal provided on one end face of an insulator arranged on the side face of a stator core; and an input terminal fixed to a cylindrical casing made of resin surrounding the stator core, wherein by assembling the cylindrical casing to the stator core, the wiring terminal and the input terminal are connected.
According to another aspect of the present invention, the invention is achieved by a permanent-magnet type brushless motor comprising: a wiring terminal provided on one end face of an insulator arranged on a side face of a stator core; a cylindrical casing made of a resin surrounding the stator core; and a connector which is fit and fixed on one end of the casing and in which an input terminal is embedded, wherein by assembling the connector to the cylindrical casing, the wiring terminal and the input terminal are connected.
Preferably, the same wiring terminal is used for a terminal wire of the stator coil and a neutral point connection, the wiring terminal for the terminal wire is embedded in a cavity formed on the outer periphery of the insulator and the wiring terminal on the neutral point side is embedded in a state of a series of the same terminals like a chain.
Preferably, the connector has a projection in a shape which is fit into a loop slop formed on the outer face of the casing.
According to further another aspect of the present invention, the invention is achieved by a permanent-magnet type brushless motor having a rotor obtained by integrally forming a rotor magnetic pole constructed by a cylindrical multi-pole anisotropic magnet and a shaft by a cylindrical casing made of a resin holding therein a stator core and an elastic insulating member having rigidity lower than at least that of the shaft, wherein the inner diameter of the casing into which the stator core and a bearing supporting the rotor are fit has a press-fit dimension in which the inner diameter of the casing is smaller than a reference dimension at the time of cooling when the ambient temperature is lower than approximately 70xc2x0 C. and has a loose dimension in which the inner diameter of the casing is larger than the reference dimension when the ambient temperature is higher than 70xc2x0 C., thereby enabling the stator core and the bearing part of the rotor to be simultaneously inserted upon assembly.
According to further another aspect of the present invention, there is provided an air conditioner using a permanent-magnet type brushless motor, wherein a softening temperature of an insulating film of a stator coil wound around a stator core is set to a value lower than a flashing point temperature of a resin material for insulation provided between the coil and the stator core and is set to a value lower than a flashing point temperature of a casing made of a resin surrounding the stator core.